What Patients Need to Know About Medical Marijuana

marijuana plant

Our pharmacist expert discusses important facts about medicinal cannabis, also known as medical marijuana.

With the opening of state dispensaries in the news, more people are interested in learning about medicinal cannabis. Christine Roussel, PharmD, BCOP, is Associate Director of Pharmacy for Doylestown Hospital. She has studied the chemical composition of medicinal cannabis, known commonly as medical marijuana, and has extensive knowledge of its uses for certain diseases. She has educated physicians and pharmacists about medical marijuana. Dr. Roussel identifies several important points patients need to know about the topic.


According to the commonwealth, "Under Act 16 (the Pennsylvania Medical Marijuana Act or the Act), the term "medical marijuana" refers to marijuana obtained for a certified medical use by a Pennsylvania resident with a serious medical condition."

Pennsylvania is one of 30 states (plus Puerto Rico, Washington DC and Guam) to allow medical use of marijuana in the U.S.

Medical vs. Recreational Marijuana

"There is a difference in the quality of the product between what you buy in a state-licensed dispensary and what you can buy on the street," says Dr. Roussel.

Approved medical marijuana is grown in accordance to strict guidelines and is safe from pesticides and solvents often used when growing and processing non-medicinal plants. The chemical composition of medical marijuana can be proven, and its effects are reliable. That is, it produces the same effect each time, which is important when taking any medication.

The main active chemicals, or medicinal compounds, in medicinal marijuana are Tetrahydrocannabinol (THC) and cannabidiol (CBD). The quantities of each chemical, or the ratio of the two, must be proven by laboratory analysis before being sold in a state dispensary.

With illicit marijuana, a person does not know where the product has been grown and stored, its exposure to heat and mold, and the amount and ratio of the chemical compounds. In other words, its potential effects are unknown to the user.

Conditions treated by medical marijuana

Currently the Pennsylvania Department of Health spells out 21 serious medical conditions that allow the patient to obtain a medical marijuana product. They include Alzheimer's disease, multiple sclerosis (MS), severe chronic pain, cancer, HIV/AIDS, epilepsy, seizures and glaucoma. The newest serious medical condition added to the list is addiction substitution therapy in patients with opioid use disorder

"Pain is one of the number one reasons why people take medicinal cannabis," says Dr. Roussel. "Next after that is MS."


"(These products) are not for everybody," cautions Dr. Roussel

People with unstable heart disease, a history of irregular heartbeat (arrhythmia) or trouble controlling blood pressure may not be good candidates for medical marijuana, which may cause increased heart rate and blood pressure or unsteadiness on their feet

For anyone, too great a dose of the medicinal compounds in medical marijuana can cause dizziness, headache or diarrhea. There are some drug interactions associated with medical marijuana. Women who are pregnant or lactating should not use medical marijuana

Other precautions include that it is not safe to drive while using medical marijuana. In fact, it is illegal

These issues highlight the importance of discussing using medical marijuana with a doctor, starting at the lowest dose possible and continuing to receive guidance from a doctor. Just like with other medications, patients may not receive relief with the first dose, and must show patience before taking more or increasing the dose.

"It's so important to have that relationship with your doctor if you're even considering trying one of these products," notes Dr. Roussel

Access for certified patients

Dr. Roussel recommends a patient start the discussion with their primary care physician, who may then refer to a physician certified to prescribe medical marijuana. The state website includes a list of currently certified physicians throughout Pennsylvania. Only a practitioner approved by the Department of Health can issue a patient certification. The state issues a medical marijuana ID card that can be taken to a state-approved dispensary. Hospitals cannot dispense medical marijuana. Insurance does not cover medical marijuana.

Only Pennsylvania residents may access medical marijuana through a state-approved dispensary. A pharmacist or doctor has to be on site at the dispensary and decide which products a patient receives. It is important to realize that this is a state program, and that marijuana remains illegal at the federal level and is not FDA approved. It is illegal to take medical marijuana across state lines.

Approved forms of medicinal marijuana in Pennsylvania include pills, liquids, oils or tinctures and ointments or patches. Liquid and dry flower may be taken through a vaporizer or nebulizer. Edible forms of marijuana are not allowed in Pennsylvania, since the amount of medicinal compounds cannot be assured in different portions. Also, children may accidentally eat a food that contains medical marijuana.

Medical marijuana can be a complementary medicine, as in pain management, but is not meant to replace traditional medications.

"In general, Pennsylvania has a very thoughtful and well rolled out program," says Dr. Roussel, who recommends patients check the Pennsylvania Medical Marijuana Program for more information.

Learn more about Pennsylvania's Medical Marijuana Program


About Doylestown Health

Doylestown Health is a comprehensive healthcare system of inpatient, outpatient and wellness education services connected to meet the health needs of all members of the local and regional community. Doylestown Hospital, the flagship to Doylestown Health has 271 beds and a Medical Staff of more than 435 physicians in over 50 specialties. An independent nonprofit health system, Doylestown Health is dedicated to providing innovative, patient-centered care for all ages.

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